| /* |
| * Copyright (C) 2003-2020 Apple Inc. All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY |
| * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY |
| * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include "config.h" |
| #include "SimpleColor.h" |
| |
| namespace WebCore { |
| |
| SimpleColor premultiplyFlooring(SimpleColor color) |
| { |
| auto [r, g, b, a] = color; |
| if (!a || a == 255) |
| return color; |
| return makeSimpleColor(fastDivideBy255(r * a), fastDivideBy255(g * a), fastDivideBy255(b * a), a); |
| } |
| |
| SimpleColor premultiplyCeiling(SimpleColor color) |
| { |
| auto [r, g, b, a] = color; |
| if (!a || a == 255) |
| return color; |
| return makeSimpleColor(fastDivideBy255(r * a + 254), fastDivideBy255(g * a + 254), fastDivideBy255(b * a + 254), a); |
| } |
| |
| static inline uint16_t unpremultiplyChannel(uint8_t c, uint8_t a) |
| { |
| return (fastMultiplyBy255(c) + a - 1) / a; |
| } |
| |
| SimpleColor unpremultiply(SimpleColor color) |
| { |
| auto [r, g, b, a] = color; |
| if (!a || a == 255) |
| return color; |
| return makeSimpleColor(unpremultiplyChannel(r, a), unpremultiplyChannel(g, a), unpremultiplyChannel(b, a), a); |
| } |
| |
| |
| } // namespace WebCore |